fix registration mobile layout

templates/bootstrap/forms/registration.html

@@ -3,7 +3,7 @@
 
 {% spaceless %}
     <div class="row">
-        <div class="col-sm-6 col-12">
+        <div class="col-sm-6 col-6">
             {% if "captcha" in field.id_for_label %}
                 {{ field.field.widget.image_and_audio|safe }}
             {% elif "agreement" in field.id_for_label %}
@@ -17,7 +17,7 @@
                 {{ field.label }}{% if field.field.required %}<span class="require">*</span>{% endif %}
             {% endif %}
         </div>
-        <div class="col-sm-6 col-12">
+        <div class="col-sm-6 col-6">
             <div class="row">
                 {% if "captcha" in field.id_for_label %}
                     {{ field.field.widget.hidden_field|safe }}